This invention targets a long well known, large environmental problem, previously unsolved, that when ships ‘on the open seas’ burn cheap low grade heavy bunker oils and other heavy residues high in sulfur, nitrogen and metals, the oxides of sulfur, nitrogen and metals go to the environment. Such emissions are worldwide, not recognizing domestic geographical boundaries. Various third party reports indicate that certain global emissions generated by marine burning of such heavy fuels for water transport are many multiples higher than combined worldwide on short vehicle fleets burning gasoline and diesel fleets. Such marine burning produces emissions of SOx, NOx, CO2, soot and noxious metals. On shore vehicle fleets include cars, trucks, and others, many of which are now using mandated “highway fuels” having very low sulfur content. Thus, even if transport by such large ships is efficient based on ‘ton of freight per mile’ and fuel consumed basis, the reality is such ships generate large emissions.
Implementation of certain key regulations mandating ships' use of clearer burning marine fuels is conditional upon sufficient quantities of such fuels being available. Rightly so to not command that which is not possible or practical, either technically or economically, yet a solution is needed.
For example, the International Maritime Organization (IMO), a division of the United Nations, issues regulations pertaining to international shipping. IMO has sought to reduce emissions by issuing more stringent sulfur limits for maritime fuels, while recognizing technical constraints. IMO has required fuels that marine fuels fired after 2011 at open sea must have a sulfur content not exceeding 3.50% m/m (e.g. fired outside defined Emission Control Areas (ECAs) including 200 nautical miles from shores of United States, Europe and certain other areas). At 2015, IMO revised its regulations to limit marine fuel sulfur content to generally less then 0.1% sulfur for commercial ships within designated ECAs.
Yet for 2020 and later, IMO has again dropped open sea sulfur limits significantly to 0.50% m/m. However, IMO notes such aggressive drop in 2020 depends “on the outcome of a review, to be concluded by 2018, as to the availability of the required fuel oil” and suggests possible deferral of such drop to 2025 if required fuels are not available. See the Convention on Marine Pollution (MARPOL), Annex VI, for regulations of Air Pollution in the Maritime Industry. Thus there is real, significant likelihood of a problem with lack of supply availability of low sulfur marine fuels and lack of technology to achieve such supply. For illustration, an industry publication in 2015 stated that “plans are in place to reduce the sulfur content allowed in fuels to below the [2014] levels required in Emission Control Areas . . . but this is years away because current technology would make that cost prohibitive for many shipping companies. Such publication further states that “due to the extra costs and possible mechanical issues, these regulations are continuously reevaluated and phased approaches are used for implementation” since many marine engines are not designed to handle low sulfur gas oil because it is so much thinner than heavy fuel oil and it does not have the lubrication properties of the heavy fuel oil. Companies are using various workarounds to make it work, such as chilling the fuel to increase the viscosity or injecting extra lubricant into certain parts of the engine.” Internet article published by Quora entitled “Is it true that the 15 biggest ships in the world produce more pollution than all the cars? by Josiah Toepfer, CG Office, Ship Inspector/Auditor, Casualty Investigator.
Another illustration is that, at 2015, IMO regulations dropped marine fuel sulfur content to a maximum of 0.1% sulfur for commercial ships within designated ECAs. Before entering ECAs, vessels must change fuels from sulfur rich, but low cost high sulfur heavy bunker fuel oil fired at open sea, to an expensive low sulfur fuel akin to highway diesel fuel. Drop of inside ECAs fuel sulfur from 1.00% m/m (for after 1 Jul. 2010) to 0.10% m/m for after 1 Jan. 2015 has created market supply and pricing challenges. Production and supply of such fuels for marine use for IMO related regulatory compliance competes with distillate fuel needs for highway and other onshore diesel applications and shifts available preferred feed streams, and also existing refinery apparatus and feed supply networks, away from highway use of diesel and other low sulfur distillates. Also, other technical issues arise onboard.
Regarding the 2015 IMO drop of sulfur content within ECAs, the United States Coast Guard issued alerts that “vessels using higher sulfur content fuels must change to ultra low sulfur (ULS) fuel oil to comply” with new regulations. Vessels must use ULS fuel oil on inbound and outbound transits, at the dock, and anytime within an ECA, thus each ship which uses higher sulfur content fuel oil is required to develop and implement changeover procedures for switching between residual and distillate fuels before entering ECAs. The Coast Guard further cautioned that “there are many other important technical issues associated with the use of ultra low sulfur fuel oils and fuel oil switching addressed in documents produced by class societies, insurers, engine manufacturers and industry associations” and that “the energy content of a given volume of ULS fuel oil may differ from residual fuel, such that existing throttle settings may not give the desired propeller shaft RPM or generator loads”. United States Coast Guard U.S. Department of Homeland Security Inspections and Compliance Directorate Mar. 3, 2015 Safety Alert 2-15 Washington, D.C. Ultra Low Sulfur Fuel Oil & Compliance with MARPOL Requirements Before entering and while operating within Emission Control Areas.
A stark reality is that refineries are expensive, requiring significant capital investments even for what seem like relatively minor changes to fuel product or production apparatus or addition of unit operations. In the 2003 era, European refinery assessment studies were conducted in anticipation of needs for lower levels of contaminants in marine fuels and requirements and capabilities for producing same in necessary quantities. See for example Advice on Marine Fuel, Potential price premium for 0.5% S marine fuel; Particular issues facing fuel producers in different parts of the EU; and Commentary on marine fuels market, Draft Final Report Contract Number ENV.C1/SER/2001/0063. Order Slip no C1/3/2003. European Commission—Directorate General Environment, October 2003.
Such reports suggested great challenges, such as higher costs or decreases in refinery utilization or efficiency, when seeking to produce necessary quantities of suitable marine fuels in many countries, including in some instances, absence of local basic facilities near major ports to locally make and supply such marine fuels as well as the absence of technology and apparatus to so make such fuels.
The cited reports saw only three options. A “re-blending option” (blending heavy fuel oils with low sulfur fuels) was viewed as the lowest cost option for producing low sulfur bunkers, yet such was not adequate as it would only treat the lowest quantity of material no major costs. The option had relatively small costs associated to logistics for the re-blending of different categories of heavy fuels then currently produced by the European refineries but failed on quantities.
The second alternative by increased cost is the processing lower sulfur crude oils, by replacing high sulfur content crudes, such as Arabian Light, which was reported to contain 1.8% sulfur, with lower sulfur crudes, for instance by African crudes such as Bonny Light which was reported to contain 0.14% sulfur by weight. The estimated incremental costs for marine bunkers incurred by this alternative were considered excessive burdens for reasons set forth in the reports.
Finally, the old era reports mention a third most expensive option for the production of low sulfur marine grade fuels by desulfurization of vacuum residue (VRDS). The report concludes that “it is important to notice, however, that as opposed to the degree of desulfurization required for petrol or diesel, hydrotreating of the bottom of the barrel (residue desulfurization) is not a process that refiners are currently considering to implement per se, that is if it is not coupled with some conversion of residue to lighter products. Nonetheless, if VRDS was pursued for the sole objective of desulfurization of vacuum residue, the costs of this alternative” were be about double the second alternative, and therefore even more unacceptable.
To meet IMO requirements with prior art technologies, a ship operator can bunker both high sulfur content fuel oil for use at sea and a low sulfur content for use within an ECA; however, this choice can face issues with technology of the engines, lubricity, and possible needs for different fuel injection systems for optimum operations and mechanics of switching fuels. An operator can add post combustion flue treatment apparatus which may be relatively large, expensive and complex to maintain at highest performance levels. In some instances, liquefied natural gas (LNG) can be considered for used as marine fuel where, for example, some transportation carriers of LNG may elect to use ‘boil off gas’ for fuel, yet to extend this LNG engine concept to all cargo ships would require wide spread LNG refueling stations infrastructure which is very costly, with added costs for those ports in locations which do not have local natural gas production supplies or liquefaction facilities. However, in all cases, LNG use in lieu of liquids carries with such use a real risk of methane release during either bunking by venting while refueling or incomplete combustion or otherwise during operations and maintenance. Such methane release is of concern since methane is attributed by some with many multiple times the impact as a greenhouse gas on the environment than sulfur dioxide. In a similar vein, some assert that emission reductions can be attained in marine applications by firing natural gas during shipping transport or while in port as facilitated by a harbor with a gas feed docking station. However, from one technical overview perspective, natural gas retains the methane leak issue and firing natural gas reduces CO2 emissions not because it releases less CO2, but instead, when compared to LNG, natural gas use avoids the CO2 emissions generated during processing to liquefy LNG and reduces CO2 when backing off or replacing coal for firing power plants that supply ships while in port. Development activities that push for LNG or natural gas to replace liquids as marine fuels as useful to consider but such do not provide any practical cost effective marine solution when there is a lack of worldwide gas infrastructure and new fueling infrastructure is needed, which gas distribution infrastructure is equipment and capital intense at ports in countries where local supplies of gas are not produced.
There is a need to solve these global environmental issues with marine fuels that are recognized, have going on for many years without a cost effective technical solution. In addition, availability of novel low costs fuels made by novel process configurations and apparatus should encourage ship owners to install highly efficient combined cycle propulsion power generation systems that have higher efficiency over diesel engines due to efficient use of waste heat recovery and do not have an issue with lack of fuel lubricity as do many engines when firing more expensive ultralow sulfur diesel that in limited supply.
However, there has long been a gap in effective fuels production technology causing a supply shortage of large quantities of very low sulfur marine fuels at low cost. The need to fill the gap remains.
International Energy Agency (EIA), Oil Industry and Markets Division publishes official public notes which describe processes and apparatus configurations used to produce fuel and describe conventional refinery configurations, products and margins. Terms used in herein, unless separately defined or expressly modified, shall have meaning assigned by the “Glossary, Source: U.S. Energy Information Administration (October 2016)” which is incorporated herein for all purposes. EIA publications define and discuss configurations for processing crude oils, all splitting each barrel of crude feed into multiple products for different applications or downstream processing.
The genetics of development or growth conventional refineries is somewhat root stock based on society's evolution of demands for products, evolving away from basic kerosene grade distillates for lighting toward multiple products such gasoline and diesel for vehicles, then aviation grade fuels, then feedstocks for many downstream chemicals applications. Refinery technical developments appear typically to have evolved in increments, directed as adaptations to either to maximize an amount of a given split from each barrel of crude for a particular market segment or to adapt refinery various streams for downstream chemicals production, all while retaining production of multiple products for different end use applications.
Thus, prior art refinery designs which use atmospheric crude and/or vacuum distillation units, solvent separations, hydrotreating, gasification, and many other unit operations, split each barrel of crude feed into multiple products each with different specifications for different applications or downstream processing.
In conventional refining is counter-intuitive to separate the feed into different unit effluent and then recombine all of such effluents. For illustration, EIA above reference defines and describes conventional or typical atmospheric crude oil distillation, vacuum distillation, fuel solvent deasphalting, catalytic hydrotreating, and integrated gasification-combined cycle technology, but not a configuration of such processes to convert substantially all of the crude oil feed to make a sole liquid fuel.
Within the scope of conventional refining processes are ‘upgrading’, ‘topping’ or ‘hydroskimming’ facilities. With crude upgraders, a primary objective is converting normally very heavy, highly viscous or solids-entrained materials so they can be re-processed in existing conventional refineries that process lighter, flowable materials to make a full range of fuel products, chemical feedstocks and/or petroleum coke. The upgraders are merely converting heavier to lighter density crude for feed conventional refineries that are individually designed to address sulfur to meet each of their respective downstream product specifications and reduction of sulfur or elimination of metals is not a primary objective of upgraders. The goal is upgrading source materials having extremely high densities compared to typical lower density crude sources. Heavier materials are rejected or separated out of sourced substances so resulting densities of upgraded product materials approach densities of crudes processed by existing conventional refinery equipment configurations. With regard to topping or ‘mini’ refineries, such are often located in remote or crude source opportunistic locations. Topping refineries typically split each barrel of crude feed into multiple straight run fractions targeted for naphtha, not gasoline production, with no or minimal subsequent processing except, in some limited cases, naphtha reforming for gasoline octane enhancement and hydrotreating multiple distillates to produce a variety of products. A typical topping refinery objective is to make a wide range of directly usable fuel usable products, such as gasoline, kerosene, diesel and fuel oil for local markets' consumption. In some undesirable practices of topping and use of their products or their failure to properly address residuals, harmful emissions to the environment are increased, not decreased. With hydroskimming refineries, crude is converted to multiple products akin to topping refineries, but typically with the limited addition of heavy naphtha reformers that also generate hydrogen which is consumed by hydrotreaters in producing diesels. Hydroskimmers, like topping refineries, typically make a wide range of gasoline, kerosene, diesel and fuel oil for local consumption, not just one product.
Various aspects of adapting hydrotreating, including having separate series or parallel hydrotreating reactor zones or having integrated hydrotreating reactor zones, are known in art. PCT/US1999/00478(1998) published by Cash et al, and the references cited therein, disclose integrated hydrotreating of dissimilar feeds, where hydrogen-containing and liquids-containing streams from separate hydrotreating zones are shared or combined in the manner disclosed therein. Various aspects of use of solvent separation, to extract deasphalted oil from pitch within heavy residual streams, and use the deasphalted oil as feed to hydrotreating are known in art when used to produce multiple product streams. For example, U.S. Pat. No. 7,686,941 (2010) to Brierley et al discusses solvent deasphalting for production of deasphalted oil, without cracking or degradation by separation of the feed based on solubility in a liquid solvent, such as propane or other paraffinic solvent such butane, pentane and others up to and including to heptane. The pitch remaining contains a high metals and sulfur content. The deasphalted oil can be hydrotreated for sulfur, nitrogen, concarbon and metals removal as discussed in such reference for production of several products including naphtha, kerosene, diesel and a residual material. The global market needs to have available bulk quantities of fuels low in sulfur and nitrogen and essentially free of metal contaminants to address global environmental issues on the open seas or at on-shore locations having little or no natural gas resources where high sulfur fuel oil or raw crude is used at low efficiency for power generation.
Fuel producers need designs, which are different than those that have evolved for conventional refining to produce multiple product slates. To keep costs low, the designs should be equipped, in a low capital investment manner, only with apparatus essential make bulk quantities of clean fuels in a cost effective and thermally efficient manner The designs should be targeted to make primarily marine fuel, not merely extract a relatively small fraction of each barrel of crude for marine fuels and not use the larger portion of the barrel for other applications.
What the world needs is a “game changer” novel process that provides a solution to technical problems on how to make large quantities of relatively clean liquid fuels (in an efficient form for use to avoid waste of energy expressed in short form as British Thermal Units (BTUs) in an economical manner for marine applications. Such process should have minimal required infrastructure and associated capital and operating costs since existing liquids-based marine fueling stations (for illustration those supplying high sulfur fuel oil (HSFO)) spread all over the world can be used for distribution of such fuels in lieu of having to create new infrastructures for LNG. Any such new process should directionally support making liquid BTUs available cost effectively compared to ultralow sulfur diesel (ULSD) produced primarily for automotive and truck use, which diesel available is widely available, but not used widely at sea by large marine transport carriers due to cost and lubricity issues when ULSD is used in many existing marine diesel engines.